Up size limit for script files
Up size limit for script files

Change size limit from 10MB to 50MB and clean up code a bit. A limit
still might be handy if one selects a very big file for subtitles by
accident. 50MB should be enough for even the biggest karaoke files.

sanyaade-g2g-repos/libass,Akemi/libass,torque/libass,xbmc/libass,grigorig/libass,torque/libass,sanyaade-g2g-repos/libass,blinkseb/libass,rhlee/libass,MrSmile/libass,Distrotech/libass,rhlee/libass,vault/libass,torque/libass,mwgoldsmith/libass,stps/libass,mwgoldsmith/libass,sanyaade-g2g-repos/libass,MrSmile/libass,vault/libass,richardpl/libass,pigoz/libass-ct,rhlee/libass,grigorig/libass,pigoz/libass-ct,libass/libass,tgoyne/libass,libass/libass,tgoyne/libass,stps/libass,stps/libass,richardpl/libass,Akemi/libass,asimonov-im/libass,pigoz/libass-ct,ShiftMediaProject/libass,astiob/libass,mwgoldsmith/libass,Distrotech/libass,asimonov-im/libass,xbmc/libass,blinkseb/libass,astiob/libass,ShiftMediaProject/libass,tgoyne/libass,blinkseb/libass,richardpl/libass,Distrotech/libass,Akemi/libass